Evinrude 1987 150. What size battery do I need to start it. I have a 650 cranking amp battery It isn't turning it over fast enough and drains the batter pritty quick. I just got the motor. It is on a stand and I am using a remote start switch.I have good compression spark will jomp 7/16" gap blue spark. getting fuel but won't start. I don't thing it is spinning fast enough to start.